How to Request a W-9 From a Vendor: TIN Verification and Penalties

To request a W-9 from a vendor, send them a blank Form W-9 (downloaded from irs.gov or a substantially similar substitute) before you issue the first payment, fill in your name and address as the requester at the top, transmit it through a secure channel, and document every follow-up until you have a signed form with a valid taxpayer identification number on file. The federal tax code both authorizes your request and obligates the vendor to respond, so treating W-9 collection as a condition of onboarding is the cleanest way to stay out of trouble.¹

When to Ask

Ask before you cut the first check. Most businesses make a signed W-9 a prerequisite for approving an invoice, and 30 days is a common internal deadline for the vendor to return it. The IRS does not set a specific deadline for return, so the timeline you enforce is the one that matters. Whatever you choose, log the date you sent the request and the date the form came back. That log is your best evidence of due diligence if the IRS later questions a filing.

Before sending, confirm the vendor’s legal name and business address so the request reaches a person who can act on it. Fill in the requester fields at the top of the form yourself. Completed W-9s that arrive with no requester information tend to sit in inboxes unattributed.

Two categories change the request. Foreign individuals and entities do not use Form W-9 at all; they need Form W-8BEN or another form in the W-8 series, and the withholding regime that follows is different (a 30% default rate rather than the 24% backup rate for U.S. payees).² And certain U.S. payees, including most corporations, tax-exempt organizations, and government entities, are exempt from backup withholding and often from 1099 reporting. The exception worth remembering: payments to corporations for medical and health care services and attorneys’ fees remain reportable and subject to backup withholding, so a law firm or medical provider still owes you a W-9 even if it is incorporated.³

How to Send the Form Securely

A completed W-9 carries a Social Security number or Employer Identification Number, so the transmission channel matters as much as the request itself. Encrypted email portals and tax-document platforms that require the vendor to authenticate before opening the file are the most common digital methods, and most log when the vendor opened and signed the form, giving you a built-in audit trail. Paper W-9s should go by certified mail with return receipt so delivery is provable.

If a vendor pushes back on why you need their TIN, the tax code is your answer: 26 USC 6109 requires anyone filing an information return to request the payee’s TIN and requires the payee to furnish it.¹

Electronic Signature Requirements

If you collect W-9s electronically instead of on paper, the IRS requires the system to meet specific standards. The vendor’s electronic signature must identify them, authenticate the submission, and appear as the final entry on the form. The system must also display the same perjury statement that appears on the paper W-9 and inform the vendor that signing constitutes that declaration.⁴ Commercial platforms handle these requirements out of the box. A homegrown collection portal needs to be checked against each element.

Verify the TIN Before You File

A mismatched name and TIN on a 1099 triggers IRS penalty notices and forces a scramble with the vendor. The IRS offers a free online TIN Matching program that lets you verify name-and-TIN combinations before filing, with both interactive single-lookup and bulk-upload options. To use it, you need to be registered on the IRS Payer Account File database.⁵ Running vendor TINs through this tool before year-end is one of the cheapest insurance policies in accounts payable.

If a Vendor Refuses or Stalls

You cannot shrug off a non-response and file the 1099 blank. The consequences fall on you. When a payee fails to provide a TIN, you must begin deducting 24% of each payment and remitting it to the IRS as backup withholding.⁶ That obligation kicks in immediately for new vendors. For existing vendors whose TIN the IRS flags as incorrect, you will receive a “B” notice instructing you to solicit a corrected TIN.³

One partial reprieve: if the vendor returns a signed W-9 with “Applied For” written where the TIN belongs, you can treat it as a temporary certificate and hold off on backup withholding for 60 calendar days from the date you receive it. If the TIN still has not arrived after those 60 days, backup withholding must begin.³

Document every request, reminder, and follow-up. If the IRS later assesses a penalty for a 1099 with a missing or incorrect TIN, your defense rests on showing you exercised ordinary business care and prudence in trying to get the information. The agency looks at whether you took reasonable steps to obtain the records, why they were unavailable, and whether you sought guidance when the vendor refused to cooperate.⁷ Three or four documented solicitations across the year are far more persuasive than a single email you sent in December.

One more reason not to filter your requests by expected payment size: the 2026 reporting threshold for most 1099 filings rose from $600 to $2,000, but payments can grow mid-year, and there is no time in January to chase a form you should have had in March.⁸ Collect from every U.S. vendor at onboarding.

Retaining the Completed Form

Store completed W-9s in a secure location, whether a locked cabinet or an encrypted system, and limit access to staff who need it for tax reporting.

The IRS does not publish a retention period specific to Form W-9. The general rule applies: keep any record supporting an item on a return until the period of limitations for that return expires, which is three years after filing in most situations.⁹ Employment tax records carry a separate four-year minimum.¹⁰ Because a single W-9 usually supports multiple years of 1099 filings, the practical rule is to keep it for at least three years after the last return it was used to prepare. Many businesses default to four as a buffer.

What the Penalties Look Like

Skipping W-9 collection or filing a 1099 with bad information creates dollar-for-dollar penalties per form. For returns due in 2026, the IRS assesses:

Up to 30 days late: $60 per return
31 days late through August 1: $130 per return
After August 1 or never filed: $340 per return
Intentional disregard: $680 per return, with no cap on the total

¹¹

A business that pays 50 vendors and misses the deadline entirely is looking at $17,000 in penalties before anyone checks whether the underlying information was correct. The intentional-disregard tier has no maximum. And on top of these filing penalties, failing to collect a valid TIN triggers backup withholding at 24% of every payment to that vendor; if you never actually withheld the money, you may owe it to the IRS out of your own pocket.³

Build W-9 collection into vendor onboarding, require the form before the first invoice is approved, run the TIN through the IRS matching tool, and set a reminder 60 days before year-end to chase anyone still outstanding. The work happens once per vendor. The penalties for skipping it recur every filing season.

1
Office of the Law Revision Counsel. 26 USC 6109 – Identifying Numbers
2
Internal Revenue Service. About Form W-8 BEN – Certificate of Foreign Status of Beneficial Owner for United States Tax Withholding and Reporting
3
Internal Revenue Service. Instructions for the Requester of Form W-9
4
Internal Revenue Service. Announcement 98-27 – Electronic Submission of Forms W-9
5
Internal Revenue Service. Taxpayer Identification Number (TIN) Matching
6
Office of the Law Revision Counsel. 26 USC 3406 – Backup Withholding
7
Internal Revenue Service. Reasonable Cause and Good Faith
8
Internal Revenue Service. Publication 1099 – General Instructions for Certain Information Returns (2026)
9
Internal Revenue Service. How Long Should I Keep Records
10
Internal Revenue Service. Recordkeeping
11
Internal Revenue Service. Information Return Penalties